It wasn’t long ago that the Chargers were the bullies of the AFC West and legitimate Super Bowl contenders.

That’s no longer the case. San Diego carries a three-season streak without a playoff appearance into 2013 and sits well behind Denver in the division pecking order.

The Chargers are in transition. They have a new coach (Mike McCoy) and general manager (Tom Telesco) charged with getting the most of what’s left of the core built by their predecessors while revamping the roster with an eye on a better future.

Perhaps no one better defines these Chargers than quarterback Philip Rivers. At his best, he’s a top performer, but he’s made a surprising number of mistakes the last two seasons.

At 32, can Rivers put together the Pro Bowl-caliber season he may well need for San Diego to contend for a playoff spot? Will the skill-position talent around him rise to occasion, too? And how will a defense with some good starters but some real questions in the secondary hold up?

Let’s take a closer look at the Chargers entering 2013:

Strengths.

The Chargers’ offense will have moments where it’s tough to stop. For all the lamenting about Rivers, he threw 11 more touchdowns than interceptions in 2012. Give him the time he needs to scan the field and he can still hurt a defense.

The Chargers also have a good hand to play at running back. Ryan Mathews has had some rotten injury luck, but he’s two seasons removed from making the Pro Bowl, and he’s capable of becoming one of the league’s better all-around threats at his position. Reserves Danny Woodhead and Ronnie Brown will help in the passing game and give Mathews the occasional breather. They are pros who play their roles well.

The Chargers’ defense has a standout in free safety Eric Weddle and talented starters throughout every position group. The three-player defensive line (nose guard Cam Thomas, ends Corey Liguet and Kendall Reyes) is young and potential-laden.

Telesco did well to sign ex-Colt Dwight Freeney after outside linebacker Melvin Ingram tore his ACL. Freeney could help the Chargers’ pass rush, which needed a lift after Shaun Phillips (team-high 9.5 sacks in 2012) wasn’t re-signed.

Weaknesses.

The Chargers’ pass protection was awful a season ago, and Rivers paid the price. On paper, the Chargers’ line looks a little better than in 2012, when Rivers was sacked a career-worst 49 times, but San Diego may still be vulnerable on the edges even after signing left tackle Max Starks and drafting right tackle D.J. Fluker. Starks and Fluker could be put to the test by skilled pass rushers.

On defense, the Chargers’ pass rush and pass coverage are areas to watch. Freeney — the oldest player on the roster — looks like the only consistent edge threat at outside linebacker.

The Chargers will have two new starters at cornerback, with ex-Jaguar Derek Coxand Shareece Wright the likely top tandem. Cox flashed ability in four seasons with the Jaguars, but his durability hasn’t been a strength. Wright, meanwhile, has yet to start an NFL game. The depth at cornerback is something of a concern, and the same can be said for the defensive line and outside linebacker as well.

Changes.

For the first time since 2007, the Chargers will have someone other than Norv Turner calling the plays. New offensive coordinator Ken Whisenhunt takes over those duties, but McCoy’s likely to have a strong voice in the offense, too. McCoy’s ability to adapt schematically to both Tim Tebow and Peyton Manning in Denver suggests he will know how to play to Rivers’ strengths.

The Chargers’ offensive line will have starters at four new positions. With Fluker arriving, former right tackle Jeromy Clary will kick inside to right guard, replacingLouis Vasquez, who signed with Denver. Ex-Bill Chad Rinehart is penciled at left guard. Center Nick Hardwick is the only holdover in his old spot.

On defense, the secondary will have three new starters: two at cornerback, where Cox and perhaps Wright will replace the departed Quentin Jammer andAntoine Cason; and one at strong safety, where Marcus Gilchrist looks to get the first shot at the job.

One notable free-agent departure was outside linebacker Antwan Barnes, who signed with the Jets. Barnes’ pass-rush ability could be missed. Also, the Chargers released injury-prone left tackle Jared Gaither after a disappointing season.

Camp battles.

The competition for playing time at wide receiver should be strong. Alexander, Floyd and Brown seem most likely to have major roles, but Meachem, Allen, Eddie Royal and Deon Butler are also in the mix. Teams looking for wideout depth late in the summer will be closely watching San Diego. A decent player or two could shake loose.

Inside linebacker is another intriguing position group. Can rookie Manti Te’o prove ready to start – and rarely leave the field – in Year One? If not, it could open the door for veterans like Jonas Mouton and ex-Packer D.J. Smith.

Finally, the cornerback and safety play bears watching. We can pencil in Cox at cornerback and Weddle at free safety, but there are some questions thereafter. That said, there’s also an opportunity for some players to prove they can play on the pro level.

Prospects.

First, the good news about the Chargers’ schedule: four of the final five games are home. However, to have a shot at a playoff berth in December, the Chargers are going to have to survive October and November, when they have just two home games — both against AFC playoff entrants from a season ago (Indianapolis, Denver).

The Chargers’ season-opener vs. Houston on Sept. 9 could tell us a lot about San Diego right off the bat. The Texans are a good team, but they have had problems against robust passing games. If nothing else, the Chargers seem capable of at least giving Houston a stern test.

After the opener, the Chargers then have road games at Philadelphia (Sept. 15) and Tennessee (Sept. 22) before hosting Dallas (Sept. 29) to end the month. The Chargers’ first division game is Oct. 6 at Oakland.A winning record after these five games is quite possible if San Diego plays to the top of its capabilities.

The guess here is Rivers and Co. will look wonderful at times in 2013 and ordinary at others. The challenges for McCoy and Telesco are just beginning as the Chargers kick off a new era with some key players closer to the finish line than the starting gate of their careers.

I would've at least noted the Chargers are trying to fix the OL by bringing in a ton of bodies and the pass rush part can't disagree except for the fact we will get some out of both Liuget & Reyes again. I'm not surprised we are in the 20s and we deserve to be there until proven otherwise